Metal matrix composite

ABSTRACT

A metal matrix composite material includes a reinforcement phase dispersed in an aluminum or aluminum alloy matrix. The reinforcement phase includes particles having an average particle size (D50) of from 0.1 μm to 0.5 μm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 62/134,198, filed Mar. 17, 2015. That application is hereby fully incorporated by reference herein in its entirety.

BACKGROUND

The present disclosure relates to metal matrix composite materials including a reinforcement phase dispersed in a matrix phase. The matrix phase includes aluminum or an aluminum alloy. The reinforcement phase may include a reinforcement material having an average particle size (D50) is the range of from 0.1 μm to 0.5 μm, including about 0.3 μm. The disclosure also relates to methods for producing and using the composite materials.

Metal matrix composites are composite materials including a metal matrix and a reinforcing material (e.g., a ceramic material or an organic compound) dispersed in the metal matrix. The metal matrix phase is typically continuous whereas the reinforcing dispersed phase is typically discontinuous. The reinforcing material may serve a structural function and/or change one or more properties of the material. Metal matrix composites can provide combinations of mechanical and physical properties that cannot be achieved through conventional materials or process techniques. These property combinations have made metal matrix composites particularly useful in the aerospace industry.

It would be desirable to provide metal matrix composite materials having improved strength.

BRIEF DESCRIPTION

The present disclosure relates to metal matrix composite materials including a reinforcement phase dispersed in a matrix phase. The matrix phase includes aluminum or an aluminum alloy. The reinforcement phase may include a reinforcement material having an average particle size (D50) is the range of from 0.1 μm to 0.5 μm, including about 0.3 μm. The disclosure also relates to methods for producing and using the composite materials.

Disclosed in various embodiments are metal matrix composites including an aluminum or aluminum alloy matrix; and reinforcement particles dispersed in the matrix. The reinforcement particles have an average particle size (D50) of from 0.1 μm to 0.5 μm.

In some embodiments, the reinforcement particles include at least one ceramic material selected from carbides, oxides, silicides, borides, and nitrides.

The reinforcement particles may include at least one ceramic material selected from silicon carbide, titanium carbide, boron carbide, silicon nitride, titanium nitride, and zirconium oxide.

In some embodiments, the aluminum alloy includes at least one element selected from the group consisting of chromium, copper, lithium, magnesium, manganese, zinc, iron, nickel, silver, scandium, vanadium and silicon.

In other embodiments, the aluminum alloy comprises from about 91.2 wt % to about 98.6 wt % aluminum, from about 0.15 wt % to about 4.9 wt % copper, from about 0.1 wt % to about 1.8 wt % magnesium, and from about 0.1 wt % to about 1 wt % manganese.

In some embodiments, the aluminum alloy contains from about 91.2 wt % to about 98.6 wt % aluminum, from 0 wt % to about 4.4 wt % copper, from 0.8 wt % to about 1.8 wt % magnesium, from 0 wt % to about 0.9 wt % manganese, from 0 wt % to about 0.2 wt % iron, from 0 wt % to about 0.6 wt % oxygen, from 0 wt % to about 0.8 wt % silicon, and from 0 wt % to about 0.25 wt % zinc.

The aluminum alloy may include from about 91.2 wt % to about 94.7 wt % aluminum, from about 3.8 wt % to about 4.9 wt % copper, from about 1.2 wt % to about 1.8 wt % magnesium, and from about 0.3 wt % to about 0.9 wt % manganese.

In some embodiments, the aluminum alloy contains from about 92.8 wt % to about 95.8 wt % aluminum, from about 3.2 wt % to about 4.4 wt % copper, from 0 to about 0.2 wt % iron, from about 1.0 to about 1.6 wt % magnesium, from 0 to about 0.6 wt % oxygen, from 0 to about 0.25 wt % silicon, and from 0 to about 0.25 wt % zinc.

The aluminum alloy may include from about 95.8 wt % to about 98.6 wt % aluminum, from about 0.8 wt % to about 1.2 wt % magnesium, and from about 0.4 wt % to about 0.8 wt % silicon.

The average particle size may be about 0.3 μm.

In some embodiments, the composite includes from about 10 vol % to about 50 vol % of the reinforcement particles.

Disclosed in other embodiments are articles including a metal matrix composite. The metal matrix composite includes an aluminum or aluminum alloy matrix; and reinforcement particles dispersed in the matrix. The reinforcement particles have an average particle size (D50) in the range of from 0.1 μm to 0.5 μm.

Also disclosed are methods of making a metal matrix composite, comprising: high energy mixing (i) particles of an aluminum or aluminum alloy with (ii) reinforcement particles having an average particle size (D50) of from 0.1 μm to 0.5 μm; processing the mixture to achieve an even distribution of the reinforcement particles; compacting the mixture to produce a billet; and producing a final article containing the metal matrix composite.

These and other non-limiting characteristics of the disclosure are more particularly disclosed below.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the drawings, which are presented for the purposes of illustrating the exemplary embodiments disclosed herein and not for the purposes of limiting the same.

FIG. 1 is a flow chart illustrating a non-limiting example of a method for producing a composite material according to the present disclosure.

FIG. 2 is a graph showing the 0.2% yield strength versus the amount of SiC particles.

FIG. 3 is a graph showing the 0.2% yield strength versus the particle size, for two different amounts of reinforcement particles. The y-axis is in units of MPa, and runs from 300 to 700 in intervals of 50. The x-axis is in units of microns, and is semi-log with units of 0.1, 1, 10, and 100 microns.

FIG. 4 is a graph showing the stress-strain curves of three different materials, one being the metal matrix composite of the present disclosure.

FIG. 5 is a graph showing the stress-strain curves for extruded product containing the same amount of reinforcement particles, but different average particle sizes.

FIG. 6 is a graph showing the 0.2% offset yield strength versus the fracture toughness, showing predicted and actual values. The y-axis is in units of MPa, and runs from 300 to 600 in intervals of 50. The x-axis is in units of MPa·m^(1/2), and runs from 10 to 26 in intervals of 2.

DETAILED DESCRIPTION

A more complete understanding of the components, processes and apparatuses disclosed herein can be obtained by reference to the accompanying drawings. These figures are merely schematic representations based on convenience and the ease of demonstrating the present disclosure, and are, therefore, not intended to indicate relative size and dimensions of the devices or components thereof and/or to define or limit the scope of the exemplary embodiments.

Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function.

The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

As used in the specification and in the claims, the term “comprising” may include the embodiments “consisting of” and “consisting essentially of.” The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named components/steps and permit the presence of other components/steps. However, such description should be construed as also describing compositions or processes as “consisting of” and “consisting essentially of” the enumerated components/steps, which allows the presence of only the named components/steps, along with any impurities that might result therefrom, and excludes other components/steps.

Numerical values in the specification and claims of this application should be understood to include numerical values which are the same when reduced to the same number of significant figures and numerical values which differ from the stated value by less than the experimental error of conventional measurement technique of the type described in the present application to determine the value.

All ranges disclosed herein are inclusive of the recited endpoint and independently combinable (for example, the range of “from 2 to 10” is inclusive of the endpoints, 2 and 10, and all the intermediate values).

The term “about” can be used to include any numerical value that can vary without changing the basic function of that value. When used with a range, “about” also discloses the range defined by the absolute values of the two endpoints, e.g. “about 2 to about 4” also discloses the range “from 2 to 4.” The term “about” may refer to plus or minus 10% of the indicated number.

The present disclosure relates to materials having an average particle size. The average particle size is defined as the particle diameter at which a cumulative percentage of 50% (by volume) of the total volume of particles are attained. In other words, 50 vol % of the particles have a diameter above the average particle size, and 50 vol % of the particles have a diameter below the average particle size.

The present disclosure relates to metal matrix composite materials including a reinforcement phase dispersed in a matrix phase. The matrix phase includes aluminum or an aluminum alloy. The reinforcement phase may include a reinforcement material having an average particle size (D50) is the range of from 0.1 μm to 0.5 μm, including about 0.3 μm. The disclosure also relates to methods for producing and using the composite materials.

Particle-reinforced aluminum alloys offer an increased elastic modulus as a function of the vol % or reinforcement material added. Existing materials offer medium strength levels. However, greater strength is desirable for many applications (particularly in space, defense, aerospace, automotive, OEM, consumer goods, and transportation applications). The refinement of reinforcement particles provides the potential for high tensile strength materials without negatively impacting secondary properties (e.g., ductility).

Reinforcement particles having an average particle size in the range of from 0.1 μm to 0.5 μm (e.g., about 0.3 μm) offer enhanced strength over particles of larger size. These finer reinforcement materials allow the production of composite materials that can be machined with conventional tools and with low tool wear. Furthermore, the finer reinforcement materials offer advantages in forming processes (e.g., extrusion) to very close precision shapes without tool wear, thereby allowing the use of conventional tools (e.g., steel H13 dies) during extrusion. The finer reinforcement materials also allow higher tensile strength to be achieved in heat treatments that allow low residual stress (high stability) conditions. The finer reinforcement materials may also allow enhanced elevated temperature properties and/or strength stability after soaking at medium and high temperatures.

When low and medium strength 2xxx and 6xxx aluminum alloys are utilized as the matrix alloy, their strengths can be increased to levels equivalent to or greater than 7xxx aluminum alloys.

Good corrosion and stress corrosion performance can be achieved as a result of the lower solute content matrix alloys. This results in strength and modulus increases which are useful for designing lightweight structural components.

The composite material may include from about 10 vol % to about 50 vol % of the reinforcement particles, including from about 15 vol % to about 30 vol % and from about 20 vol % to about 25 vol %.

In some embodiments, the aluminum alloy includes from about 91.2 wt % to about 94.7 wt % aluminum, from about 3.8 wt % to about 4.9 wt % copper, from about 1.2 wt % to about 1.8 wt % magnesium, and from about 0.3 wt % to about 0.9 wt % manganese.

In other embodiments, the aluminum alloy includes from about 95.8 wt % to about 98.6 wt % aluminum, from about 0.8 wt % to about 1.2 wt % magnesium, and from about 0.4 wt % to about 0.8 wt % silicon.

In some embodiments, the aluminum alloy is a 2000 series aluminum alloy (i.e., aluminum alloyed with copper), a 6000 series aluminum alloy (i.e., aluminum alloyed with magnesium and silicon), or a 7000 series aluminum alloy (i.e., aluminum alloyed with zinc). Non-limiting examples of suitable aluminum alloys include 2009, 2124, 2090, 2099, 6061, and 6082.

The aluminum alloy may be 2009. The composition of 2009 aluminum alloy is as follows:

Component Wt % Aluminum 92.8-95.8 Copper 3.2-4.4 Iron 0.05 max Magnesium 1.0-1.6 Other, each 0.05 max Other, total 0.15 max Oxygen 0.60 max Silicon 0.25 max Zinc 0.10 max

The aluminum alloy may be 2090. The composition of 2090 aluminum alloy is as follows:

Component Wt % Aluminum 93.2-95.6 Chromium 0.05 max Copper 2.4-3.0 Iron 0.12 max Lithium 1.9-2.6 Magnesium 0.25 max Manganese 0.05 max Other, each 0.05 max Other, total 0.15 max Silicon 0.10 max Titanium 0.15 max Zinc 0.10 max Zirconium 0.08-0.15

The aluminum alloy may be 2099. The composition of 2099 aluminum alloy is as follows:

Component Wt % Aluminum 92.51-95.35 Beryllium 0.0001 max Copper 2.4-3.0 Iron 0.07 max Lithium 1.6-2.0 Magnesium 0.10-0.50 Manganese 0.10-0.50 Other, each 0.05 max Other, total 0.15 max Silicon 0.05 max Titanium 0.10 max Zinc 0.40-1.0  Zirconium 0.05-0.12

The aluminum alloy may be 2124. The composition of 2124 aluminum alloy is as follows:

Component Wt % Aluminum 91.2-94.7 Chromium Max 0.1 Copper 3.8-4.9 Iron Max 0.3 Magnesium 1.2-1.8 Manganese 0.3-0.9 Other, each Max 0.05 Other, total Max 0.15 Silicon Max 0.2 Titanium Max 0.15 Zinc Max 0.25

The aluminum alloy may be 6061. The composition of 6061 aluminum alloy is as follows:

Component Wt % Aluminum 95.8-98.6 Chromium 0.04-0.35 Copper 0.15-0.4  Iron  0.7 max Magnesium 0.8-1.2 Manganese 0.15 max Other, each 0.05 max Other, total 0.15 max Silicon 0.4-0.8 Titanium 0.15 max Zinc 0.25 max

The aluminum alloy may be 6082. The composition of 6082 aluminum alloy is as follows:

Component Wt % Aluminum  95.2-98.3 Chromium 0.25 max Copper 0.10 max Iron 0.50 max Magnesium 0.60-1.2 Manganese 0.40-1.0 Other, each 0.05 max Other, total 0.15 max Silicon 0.70-1.3 Titanium 0.10 max Zinc 0.20 max

The reinforcement particles may include at least one material selected from carbides, oxides, silicides, borides, and nitrides. In some embodiments, the material is selected from silicon carbide, titanium carbide, boron carbide, silicon nitride, titanium nitride, and zirconium oxide.

FIG. 1 is a flow chart illustrating an exemplary method 100 of the present disclosure. The method includes providing metal particles (e.g., aluminum or aluminum alloy particles) 105 and providing reinforcement particles (e.g., ceramic particles) 110 to a high energy mixing stage 120.

The metal and ceramic powders should be mixed with a high energy technique to distribute the ceramic reinforcement particles into the metal matrix. Suitable techniques for this mixing include ball milling, mechanical attritors, teamer mills, rotary mills and other methods to provide high energy mixing to the powder constituents. Mechanical alloying should be completed in an atmosphere to avoid excessive oxidation of powders preferable in an inert atmosphere using nitrogen or argon gas. The processing parameters should be selected to achieve an even distribution of the ceramic particles in the metallic matrix.

The powder from the high energy mixing stage is degassed to remove any retained moisture from the powder surface, this may be completed at between 120 to 500° C.

A hot compacting step may also be performed to increase density and produce a billet 140. The hot compacting may be performed at a temperature in the range of from about 400° C. to about 600° C., including from about 425° C. to about 550° C. and about 500° C. Hot compaction may include the use of hot die compaction, hot isostatic pressing or hot extrusion typically at pressures of between 30 to 150 MPa.

In particular, hot isostatic pressing is contemplated for making the billet. In the HIP process, the powder is exposed to both elevated temperature and high gas pressure in a high pressure containment vessel, to turn the powder into a compact solid, i.e. a billet. The isostatic pressure is omnidirectional. The HIP process eliminates voids and pores. The hot isostatic pressing may be performed at a temperature of 1000° C. to 1200° C. and a pressure of 30 to 150 MPa for a period of sufficient to allow the metal section to reach the required temperature, typically between 1 and 8 hours. The hot isostatic pressing may be performed on commercially available steel or nickel HIP systems.

The billet may be subsequently processed 150 into a final article. This processing may include rolling, extrusion, or machining, without hot working. In accordance with one embodiment, the billet is rolled or extruded into an intermediate article. Final machining, e.g., CNC, is performed on the intermediate article resulting in a final article.

The resulting articles/metal matrix composite may have a 0.2% offset yield strength of about 400 MPa to about 680 MPa; an elastic modulus of about 80 GPa to about 150 GPa; or about 3% to about 8% elongation to failure, as measured according to ASTM E8M. It is noted that these properties are usually measured in articles of specific shapes, but for purposes of convenience are also attributed to the metal matrix composite itself. Combinations of these properties are also specifically contemplated. The articles have a balance of high strength and high elastic modulus with good ductility. Elastic modulus can be related to the vol % of reinforcement particles (e.g., SiC particles) added. For example, 20 vol % SiC particles may lead to an elastic modulus of 115 GPa, an increase of 43 GPa or about 1.72 GPa per vol % SiC particles.

FIG. 6 is a graph showing unexpected results. The graph shows the 0.2% offset yield strength versus the fracture toughness of the metal matrix composite. The x-axis is a measure of the resistance of the material to the propagation of a crack. The yield strength for a metal matrix composite made of 2124 aluminum and 17 vol % of SiC particles with a particle size of 0.3 μm was almost 100 MPa higher than expected.

The following examples are provided to illustrate the compositions, articles, and methods of the present disclosure. The examples are merely illustrative and are not intended to limit the disclosure to the materials, conditions, or process parameters set forth therein.

EXAMPLES

Billets were produced from a metal matrix composite. The metal matrix composite included silicon carbide particles dispersed in an aluminum alloy T4 temper 2124 matrix. The silicon carbide particles had three different average particle sizes (D50) of 3 micrometers (pm), 0.7 μm, and 0.3 μm.

FIG. 2 is a graph showing the 0.2% yield strength versus the amount of SiC particles. As seen here, the 0.2% yield strength increased proportionally with the amount of particles. However, the smaller particles had a higher 0.2% yield strength for the same amount.

FIG. 3 is a graph showing the 0.2% yield strength versus the particle size, for two different amounts of particles (squares are 17 vol %, triangles are 25 vol %). As the particle size decreased, the 0.2% yield strength increased at a higher rate.

Next, billets were forged at a 2:1 forge ratio or extruded at a 34:1 extrusion ratio. Billets were made from a metal matrix composite containing 17 vol % of SiC particles having an average particle size of 0.3 microns. The results are provided in the Table below:

Property Unit Billet Forged Extruded Orientation N/A Any L L Ultimate Tensile Strength MPa 630 640 670 0.2% Yield Strength MPa 580 560 545 Elastic Modulus GPa 98 Strain to Failure % 2 3 7 Density g/cm³ 2.85

The forged plates were quenched. The forged plate light reduction ratio was 2:1. The results are provided in the Table below. “T4 CWQ” is cold water quench, “T6 HWQ” is hot water quench, and “T6 PGQ” is Polymer glycol quench.

Property Unit T4 CWQ T6 HWQ T6 PGQ Yield Strength (R_(p0.2)) MPa 563 548 496 Ultimate Tensile Strength (R_(m)) MPa 637 627 567 Elongation to Failure (A_(t)) % 2.4 3.1 3.2

FIG. 4 is a graph showing the stress-strain curves of three different materials. The top line is a billet made from an aluminum metal matrix composite containing 17 vol % of SiC particles having an average particle size of 0.3 microns. The middle line is a billet made from aluminum alloy 7075 T651 plate-T. The bottom line is a billet made from aluminum alloy 7075 T651 plate-ST. The billet made from the metal matrix composite with reinforcement particles of 0.3 microns average size had the best performance.

FIG. 5 is a graph showing the stress-strain curves for extruded product at 34:1 extrusion ratio in T6 CWQ and containing 17 vol % of SiC particles at three different particle sizes. Again, the stress-strain curve is highest for the smallest particle size.

The present disclosure has been described with reference to exemplary embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the present disclosure be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. 

1. A metal matrix composite comprising: an aluminum or aluminum alloy matrix; and reinforcement particles dispersed in the matrix, the reinforcement particles having an average particle size (D50) of from 0.1 μm to 0.5 μm.
 2. The metal matrix composite of claim 1, wherein the reinforcement particles comprise at least one ceramic material selected from the group consisting of carbides, oxides, silicides, borides, and nitrides.
 3. The metal matrix composite of claim 1, wherein the reinforcement particles comprise at least one ceramic material selected from the group consisting of silicon carbide, titanium carbide, boron carbide, silicon nitride, titanium nitride, and zirconium oxide.
 4. The metal matrix composite of claim 1, wherein the aluminum alloy comprises at least one element selected from the group consisting of chromium, copper, lithium, magnesium, manganese, zinc, iron, nickel, silver, scandium, vanadium and silicon.
 5. The metal matrix composite of claim 1, wherein the aluminum alloy comprises from about 91.2 wt % to about 98.6 wt % aluminum, from about 0.15 wt % to about 4.9 wt % copper, from about 0.1 wt % to about 1.8 wt % magnesium, and from about 0.1 wt % to about 1 wt % manganese.
 6. The metal matrix composite of claim 1, wherein the aluminum alloy comprises from about 91.2 wt % to about 94.7 wt % aluminum, from about 3.8 wt % to about 4.9 wt % copper, from about 1.2 wt % to about 1.8 wt % magnesium, and from about 0.3 wt % to about 0.9 wt % manganese.
 7. The metal matrix composite of claim 1, wherein the aluminum alloy comprises from about 92.8 wt % to about 95.8 wt % aluminum, from about 3.2 wt % to about 4.4 wt % copper, from 0 to about 0.2 wt % iron, from about 1.0 to about 1.6 wt % magnesium, from 0 to about 0.6 wt % oxygen, from 0 to about 0.25 wt % silicon, and from 0 to about 0.25 wt % zinc.
 8. The metal matrix composite of claim 1, wherein the aluminum alloy comprises from about 95.8 wt % to about 98.6 wt % aluminum, from about 0.8 wt % to about 1.2 wt % magnesium, and from about 0.4 wt % to about 0.8 wt % silicon.
 9. The metal matrix composite of claim 1, wherein the average particle size of the reinforcement particles is about 0.3 μm.
 10. The metal matrix composite of claim 1, wherein the composite comprises from about 15 vol % to about 50 vol % of the reinforcement particles.
 11. The metal matrix composite of claim 1, wherein the metal matrix composite has a 0.2% offset yield strength of about 400 MPa to about 680 MPa; an elastic modulus of about 80 GPa to about 150 GPa; and about 3% to about 8% elongation to failure, measured according to ASTM E8M.
 12. A method for making a metal matrix composite, comprising: high energy mixing (i) particles of an aluminum or aluminum alloy with (ii) reinforcement particles having an average particle size (D50) of from 0.1 μm to 0.5 μm; and processing the mixture to achieve an even distribution of the reinforcement particles.
 13. The method of claim 12, wherein the high energy mixing is performed in an inert atmosphere.
 14. The method of claim 12, wherein the reinforcement particles comprise at least one ceramic material selected from the group consisting of carbides, oxides, silicides, borides, and nitrides.
 15. The method of claim 12, wherein the aluminum alloy comprises at least one element selected from the group consisting of chromium, copper, lithium, magnesium, manganese, zinc, iron, nickel, silver, scandium, vanadium and silicon.
 16. The method of claim 12, wherein the composite comprises from about 15 vol % to about 50 vol % of the reinforcement particles.
 17. A method for producing an article from a metal matrix composite, comprising: compacting the metal matrix composite to produce a billet; and processing the billet to form the article.
 18. The method of claim 17, wherein the compacting is performed at a pressure of about 30 MPa to about 150 MPa.
 19. The method of claim 17, wherein the compacting is performed by hot isostatic pressing (HIP).
 20. An article formed from a metal matrix composite, the metal matrix composite comprising: an aluminum or aluminum alloy matrix; and reinforcement particles dispersed in the matrix, the reinforcement particles having an average particle size (D50) of from 0.1 μm to 0.5 μm. 